@nexusts/feature-flag

Feature flags, canary deployments, and A/B testing for NexusTS.

Install

bun add @nexusts/feature-flag

Quick start

import { FeatureFlagModule, FeatureFlagService, FeatureFlag } from '@nexusts/feature-flag';

@Module({
  imports: [
    FeatureFlagModule.forRoot({
      flags: {
        'new-dashboard': { enabled: true, rollout: 0.5 },
        'beta-api':      false,
      },
    }),
  ],
})
class AppModule {}

// In a controller:
const showBeta = await flags.isEnabled('new-checkout', { userId: 'u-1' });

// Or as a decorator:
@FeatureFlag('new-dashboard')
async index() { ... }

API

| Method | Description | | ------ | ----------- | | isEnabled(flag, context?) | Promise<boolean> — true if the flag is active | | setFlag(name, definition) | Add or update a flag at runtime | | getFlag(name) | Return the current definition |

Flag evaluation order: denylist → allowlist → enabled: false → rollout (djb2 hash) → default.

Links

• User guide
• NestJS comparison — feature flags